Nowadays, some high sensitive data information stored in the electronic circuit, such as bank information, passwords, poll code and so on, is often attacked and embezzled without any authorization. Therefore, more and more attention is paid to protect these data, and so all kinds of protection devices and methods are presented continuously. Among these methods, a method, which is relatively effective to prevent the sensitive data information from being attacked without any authorization, is used to prevent the sensitive data information from being embezzled by memorizing a software for encrypting or decrypting the sensitive program or data in a memory device. However, this approach relies on keys of encryption and decryption memorized in the memory device, which also require physical and electronic protection to avoid being attacked easily.